Germany's three big luxury car companies tend to move in lockstep when it comes to new vehicles. Mercedes built a four-door coupe, so Audi and BMW cranked out their own versions. BMW turned their SUV into a four-seat sports-activity coupe, so Mercedes and Audi went to work building their own. And since Audi and BMW are hard at work creating eco-friendly halo cars for their brands, it was only a matter of time until Mercedes-Benz followed suit.

According to CAR, Mercedes's answer to the Audi e-tron and BMW i3/i8 will be something called the E Superlight, a carbon fiber-bodied four-door based on the next E-Class powered by a 150 horsepower fuel cell and a 50 hp electric motor. The car's body will reportedly be so strong, it doesn't need a B-pillar; combined with rear suicide doors, this will give the E Superlight one uninterrupted entrance on each side of the car when all the doors are open.

But while the E Superlight's roughly 800 pounds of weight savings over the regular E-Class should give the carbon fiber-bodied sedan decent pep, the big news for enthusiasts is that the carbon fiber experience Mercedes gains from the Superlight will supposedly be used on the SLS AMG's replacement. While we doubt the new sports car will seem weight savings quite as significant as the Superlight's, a carbon fiber chassis should still be good for a few hundred pounds off the SLS's roughly 3,600 lb. curb weight. And of course, there's always the chance AMG will drop one of their motors into the E Superlight...[via CAR]